1. Field of the Invention
The present invention relates to an endoscope gas delivery system.
2. Description of the Related Art
A medical endoscope includes an illumination window, an observation window, and a clamp outlet provided at a front end of an insertion section. At the time of using the endoscope, the insertion section is inserted into a body cavity of a subject. Then, the inside of the body cavity is irradiated with illumination light from the illumination window, and is observed from the observation window. When a diseased area or the like is found, a high frequency treatment tool, a clamp, or the like is inserted through a clamp channel, and the diseased area is treated by the clamp or the like exiting the clamp outlet.
For this reason, the endoscope system includes a light source device, a processor, and a monitor as well as the endoscope. Furthermore, if necessary, a high frequency power supply device, a VTR, a printer, or the like is attached to the endoscope system. The various devices are installed in a cart together with the endoscope. The cart includes a plurality of stages of shelves on which various devices are installed, and is configured to be movable. The endoscope system is carried to a clinical site by the cart, and an examination or a treatment using the endoscope is performed.
The inside of the body cavity is irradiated with the illumination light, output from the light source of the light source device, through a light guide from the illumination window. An imaging unit is disposed inside a front end of the insertion section at a position facing the observation window. The imaging unit images the inside of the body cavity from the observation window. Image signals output from the imaging unit are output to the processor through a universal cord. The processor processes the image signals and displays the result on the monitor.
When an examination or a treatment is performed by the endoscope, a surgical operator (an operator) controls various devices connected to the endoscope. For example, the light source device adjusts the light amount of the light source so as to sharpen the image inside the body cavity displayed on the monitor. Furthermore, when the high frequency treatment tool is used, the voltage or the current of the high frequency power supply is appropriately controlled, and a safe and efficient treatment is performed.
The endoscope includes supply paths for a pressurized liquid and a pressurized gas. The pressurized liquid is used for various purposes. For example, the pressurized liquid is used to clean the observation window, to clean the inner wall of the body cavity, to spray a chemical liquid, and to perfuse a liquid through an organ or a tissue. The pressurized gas is used to expand the inside of the body cavity and remove liquid droplets of the cleaned observation window. As a pressurization source for a liquid and a gas, for example, an air pump is used. When the pressurized gas is supplied, the air pump is driven. Furthermore, in order to pressurize a liquid during liquid delivery, the pressurized air is supplied from the air pump to the liquid delivery tank. The air pump is generally built in the light source device. Furthermore, the liquid delivery tank is separably attached to the light source device. In addition to the on/off state of the air pump, the rotation number thereof is also controlled, so that the pressure and the flow rate of the pressurized air are changed.
In recent years, a pressurized gas source of a carbon dioxide gas (CO2) has been commercialized instead of the pressurization of air using the air pump. The carbon dioxide gas is desirable from the viewpoint that the carbon dioxide gas is more easily absorbed to the body than air, safety improves, and the burden on the patient is reduced. When the carbon dioxide gas is used as the pressurized gas source, a carbon dioxide gas supply device using a carbon dioxide gas cylinder is used. The carbon dioxide gas supply device is separably connected to a gas delivery passage of the endoscope, and supplies the carbon dioxide gas from the carbon dioxide gas cylinder in a depressurized state.
For example, JP2006-14961A proposes a gas delivery system in which a carbon dioxide gas cylinder is used as a pressurized gas source in addition to an air pump. In the gas delivery system, pressurized air may be supplied from the air pump in addition to the carbon dioxide gas from the carbon dioxide gas cylinder.